Worst Knightmare: Unlock all trophies, and get a 100% game completion.

The following costumes are unlocked through DLCs:

1st Appearance: Collector's Edition exclusive bonus.

Batman Legends Pack: Pre-order bonus (Walmart in US, JB Hi-Fi in Australia). It includes the Earth 2 Batman, Batman ThrillKiller, Dark Knight Of The Round Table, and The Long Halloween costumes.

Brightest Day: Included with Season Pass purchase.

Deathstroke: Pre-order bonus (Amazon, Best Buy, GameStop, Target, Walmart), or available for purchase.

Gotham By Gaslight: Included with Season Pass purchase.

Infinite Earths Pack: Available for purchase. It includes the Batman ThrillKiller, Classic Tim Drake Robin (1989-2006), Dark Knight Of The Round Table, Earth-2 Bruce Wayne, Earth-2 New, and The Long Halloween costumes.

Knightfall Pack: PS3 Exclusive pre-order bonus. It includes the Adam West and futuristic Batman costumes.

New 52 Metallic: DC Comics exclusive bonus.

New Millenium Pack: Available for purchase. It includes the Blackest Night 2006-2008 Tim Drake Robin, First Appearance 1939, New 52, Noel, and Red Son costumes.

Infinite XP and all upgrades

To get 120,000 XP in 15 minutes and be able to buy all upgrades at the beginning of the game, go to Burnley. Go to the indicated location on the rooftop, and let the enemy kill you so you are saved at this location. When you spawn after dying, use the grappling hook to go back to the rooftop, and silent takedown the first three enemies. Then, silent takedown the fourth enemy with a Knockout Smash (press Square) to get a total of 8,000 XP. After getting the XP and the "Saving..." icon disappears at the bottom of the screen, pause the game and select "Restart" to start from the last checkpoint. Repeat this process as many times as desired.

All Anarky Tag locations

Search the indicated locations to find all 24 Anarky Tags and get the "Voice Of The People" achievement. They also count towards the "First Riddler Trophy" achievement, which requires you to find all collectibles in the game. You can see which collectibles you have found by pressing Select and choosing "Database - Gotham Intel". Unlike the rest of the collectibles, Anarky Tags are not marked on the in-game map. After locating one, you have to scan it with Batman's detective vision. You will also get 5,000 XP for each Anarky Tag found.

Enigma Datapack/Extortion File locations

Search the indicated locations to find the Enigma Datapacks/Extortion Files. Extortion Files 1 and 2 (comprising of 20 Datapacks) are hidden throughout Park Row. To enter the Courthouse, you must complete Anarky's side mission. To enter the Church, you must complete Black Mask's side mission. Enigma has 20 Extortion Files that he is threatening to release. In order to prevent this, you must collect all of the pieces that compose each file. Each Extortion File consists of 10 Datapacks, totaling 200 pieces that are hidden around Gotham City. Collect a full set to decipher the file. For each Extortion File, there is an Enigma Data Handler, who reveals the locations of the 10 Datapacks when interrogated.

All GCR Comms Towers and Network Relay locations

Search the indicated locations to find all GCR Comms Towers and Network Relays. Enigma has placed jamming devices at each of the seven GCR Comms Towers, one in each district. Batman must figure out how to get inside the Tower Maintenance Access of each tower and hack into the security console. Once you have removed the interface, you will then have access to the Batwing Drop Point in that district, and the locations of the ten Network Relays in the area will be revealed on the in-game map. You must destroy the relay's with a Batarang.

Hidden Pinkney Plaque locations

Search the indicated locations to find all eight Pinkney Plaques. After locating a plaque, you have to scan it with Batman's detective vision. The plaques are part of a side quest that is easy to miss. The side quest requires you to solve the murder of the city's master architect, Cyrus Pinkney, by finding the hidden notes left in eight plaques around Gotham City. Completing this side quest is required to reach 100% completion in the game.

1. Old Gotham Cathedral – Park Row: It is on the roof of the church, on the back of the tower.

2. Solomon Wayne Courthouse – Park Row: It is on the backside of the horse statue, west of the courthouse building.

3. Pioneers Statue – Jezebel Mall – Bowery: It is on the roof of the bank, below the huge bell.

4. Gotham Rail – Amusement Mile: It is on the roof of the old Gotham PD building from Arkham City, in a gated hallway on the southern edge of the building.

5. Jezebel Theater – Bowery: It is to the left of the doors leading into the theater.

6. Pioneers Bridge – Gotham Bridge: It is at the top and center of the bridge, on the eastern rod.

7. Cyrus Pinkney School Of The Arts – Coventry: It is on the ground level where the highway and giant factory meet, on the southernmost rod.

8. Cyrus Pinkney's Crypt – Burnley: The final plaque only appears after finding the other plaques. Check the in-game map for a waypoint on the eastern shore of Burnley. It is in the crypt, near the tomb.

Green Arrow reference

In the interior of the Final Offer (in the same area as the "fight arena"), look for a cargo container with "Queen Industries" on its side. "Queen Industries" belongs to Oliver Queen, a.k.a. the Green Arrow.

Harvey Dent reference

Go to the evidence locker at the G.C.P.D. building to see a newspaper clipping of Harvey Dent's win in the election for Gotham City D.A.

Rupert Thorne reference

In the G.C.P.D. building, look carefully at the bulletin boards in the squadron rooms. On the walls are newspaper clippings and mugshots with police reports. One of these reports references Rupert Thorne, who is one of Gotham's infamous criminals.

Easy "Anyone See That?" and "Silent Knight" trophies

In the mission where you need to track down the Penguin on his ship (it is one of the first main missions in the game), after your encounter with Tracey (Penguin's assistant) and her goons, you will reach the first predator room in the game. Stay crouched, sneak up to an isolated enemy, and press Triangle to perform a silent takedown. Do this to all six enemies in the room, without being noticed, to get the "Anyone See That?" and "Silent Knight" trophies. Note: If you have already passed this point in the game, there are still plenty of other opportunities to get these trophies, but you should definitely do this before completing the story. After completing a predator room, the enemies will not respawn.

Easy "Flawless Display" trophy

Shiva is one of the Assassin's on the Most Wanted list. After playing through the story, go to the Gotham Merchants bank in "The Bowery" district. The starting point of Shiva's quest is not marked on the map. Listen for a crying baby, and inspect the abandoned baby stroller in front of the Gotham bank to begin this quest. You will then have to complete a series of tasks for Shiva. It does not matter if her ninjas or other enemies hit you while doing the tasks. After completing all the tasks, meet up with her in Sheldon Park (marked on your map). Successfully complete the fight with her without taking any damage to get the "Flawless Display" trophy. A good tactic to use to not get hit is to jump, hit an enemy once, and jump again. When jumping, the enemies will not have an opportunity to hit you. During the final phase of the fight, activate your Shock Gloves to defeat the enemies more quickly. If you get hit during the fight, pause the game, and choose the "Restart" option. The entire fight will start from the beginning, and you can try again. Note: It is possible to miss the Shiva fight in the story. If you miss the fight, you must start a new game and do Shiva's side quest to fight her.

Easy "Free Flow Fifty" trophy

You can easily reach a x50 combo in the first combat challenge, "Intensive Training". Enemies will not have armor or shields in this challenge. Reach Round 4 so there are enough enemies to build up a x50 combo. To ensure you do not get hit while fighting, perform a standard strike, then jump over an enemy, and repeat. None of the enemies will be able to hit you. It takes a little longer than countering and fighting the normal way, but it is much safer and easier to do. Do not perform any combo attacks or finishers -- so the enemies stay alive longer. If you have already unlocked the Shock Gloves, activate them to get a x2 multiplier with each hit.

Easy "One Of Each" trophy

There are five different gadgets needed to get the "One Of Each" trophy. They are all unlocked automatically while playing through the story. The following gadgets have to be used in one combo, without ever losing the combo multiplier:

You will fight Deathstroke during a story mission, early in the game. Every time he attacks, you must press Triangle to counter him. Attack Deathstroke with Batman's normal strike. Doing so may initiate a QTE where you need to press the counter-button when it is displayed on the screen. If you press the button too early, or too late, your counter attack will fail, and you will get hit. If you get hit during the fight, pause the game, and choose the "Restart" option. The entire fight will start from the beginning, and you can try again. Note: It is possible to miss the Deathstroke fight in the story. If you miss the fight, you must start a new game and play until you reach the Deathstroke Boss fight to get the "Point Counter-Point" trophy.

Easy "Point To Point" trophy

To get the "Point To Point" trophy, you must use the Grapnel Gun and glide across the Gotham Pioneers Bridge (the large bridge connecting the south and north of Gotham City). You can do this at any point in the game while in Free Roam mode (even after completing the story). No upgrades are required. Start at one end of the bridge, and keep shooting the Grapnel Gun at the wires to stay above ground. After shooting the Grapnel Gun, you must also activate the Accelerator by pressing X(2) to avoid touching the wires. You may not land at any point while crossing the bridge. If you do, you must start over.

Trophies

Successfully complete one of the following tasks to get a trophy:

Platinum (Platinum): Unlock all trophies.

Shut Down (Bronze): Shut down an entire Tower Network.

Counter-intelligence (Bronze): Decipher one Extortion File.

Enigma Unravelled (Bronze): Collect all Enigma items.

First Riddler Trophy (Silver): Collect every collectible.

One down, several to go (Bronze): Complete a Most Wanted entry.

The Innocent and the Predatory (Silver): Capture all of Black Mask's Assassins.